In Middle English writing, tailed z came to be indistinguishable from yogh.

In Middle Scots, the character yogh became confused with a cursive z and the early Scots printers often used z when yogh was not available in their fonts.[1] Consequently, some Lowland Scots words have a z in place of a yogh.

Yogh is shaped similarly to the Arabic numeral three (3), which is sometimes substituted for the character in online reference works. There is some confusion about the letter in the literature, as the English language was far from standardised at the time. The upper and lower case letters (Ȝ, ȝ) are represented in Unicode by code points U+021CȜLATIN CAPITAL LETTER YOGH (HTML &#540;) and U+021DȝLATIN SMALL LETTER YOGH (HTML &#541;) respectively.

In Middle English, it also stood for the phoneme /x/ and its allophone [ç] as in ⟨niȝt⟩ ("night", then pronounced as spelled: [niçt]). Sometimes, yogh stood for /j/ or /w/, as in the word ⟨ȝoȝelinge⟩ [ˈjowəlɪŋɡə], "yowling".

In Middle Scots, it represented the sound /j/ in the clusters /lj/, /ŋj/ and /nj/ written lȝ and nȝ.[4] Yogh was also used for /j/ rather than y.

The original Germanic g sound was expressed by the gyfu rune in the Anglo-Saxon futhorc (which is itself rendered as ȝ in modern transliteration). Following palatalization, both gyfu and Latin g in Old English expressed the /j/ sound before front vowels. For example, "year" was written as either ȝear or gear, even though the word had never had a g sound (deriving from Proto-Germanic*jērą).

With the re-introduced possibility of a /g/ sound before front vowels, notably in the form of loanwords from the Old Norse (such as gere from Norse gervi, Modern English gear), this orthographical state of affairs became a source for confusion, and a distinction of "real g" (/g/) from "palatalized g" (/j/) became desirable.

Normanscribes despised non-Latin characters and certain spellings in English and therefore replaced the yogh with the digraph gh; still, the variety of pronunciations persisted, as evidenced by cough, taught, and though. The process of replacing the yogh with gh was slow, and was not completed until the end of the fifteenth century. Not every English word that contains a gh was originally spelled with a yogh: for example, spaghetti is Italian, where the h makes the g hard (i.e., [ɡ] instead of [dʒ]); ghoul is Arabic, in which the gh was /ɣ/.

The medieval author Orm used this letter in three ways when writing Early Middle English. By itself, it represented /j/, so he used this letter for the y in "yet". Doubled, it represented /i/, so he ended his spelling of "may" with two yoghs. Finally, the digraph of yogh followed by an h represented /ɣ/.[5]

In words of French and Gaelic origin, the Early Scotspalatal consonant/ɲ/ had become /nj/ or in some cases /ŋj/, and the palatal consonant /ʎ/ had become /lj/ by the Middle Scots period.[4] Those were variously written nȝ(h)e, ngȝe, ny(h)e or ny(i)e, and lȝ(h)e, ly(i)e or lyhe. By the Modern Scots period the yogh had been replaced by the character z, in particular for /ŋj/, /nj/ (nȝ) and /lj/ (lȝ), written nz and lz. The original /hj/ and /çj/ developed into /ʃ(j)/ in some words such as Ȝetland or Zetland for Shetland.[1] Yogh was also used to represent /j/ in words such as ȝe, ȝhistirday(yesterday) and ȝoung but by the Modern Scots period y had replaced yogh.[6] The pronunciation of MacKenzie (and its variant spellings) (from Scottish Gaelic MacCoinnich), originally pronounced [məˈkɛŋjiː],[7] shows where yogh became zed. Menzies Campbell is another example.

In Middle Scots orthography, the use of yogh became confused with a cursive z and the early Scots printers often used z when yogh was not available in their fonts.

The yogh glyph can be found in surnames that start with a Y in Scotland and Ireland; for example the surname Yeoman, which would have been spelled Ȝeman. Sometimes, the yogh would be replaced by the letter z, because the shape of the yogh was identical to some forms of handwritten z.

In Unicode 1.0, the character yogh was mistakenly unified with the quite different character ezh (Ʒ ʒ), and yogh itself was not added to Unicode until version 3.0.

The symbol actually used in Egyptology is , two half-rings opening to the left. Since Unicode 5.1, it has been assigned its own codepoints (uppercase U+A722 Ꜣ LATIN CAPITAL LETTER EGYPTOLOGICAL ALEF, lowercase U+A723 ꜣ LATIN SMALL LETTER EGYPTOLOGICAL ALEF); a fallback is the numeral 3.